axmol/templates/cpp-template-default/proj.winrt/App.xaml

<Application
    x:Class="AxmolAppWinRT.App"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:AxmolAppWinRT">

    <Application.Resources>

      <x:String x:Key="AppName">HelloCpp</x:String>

    </Application.Resources>
</Application>